1
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Leung PM, Grinter R, Tudor-Matthew E, Lingford JP, Jimenez L, Lee HC, Milton M, Hanchapola I, Tanuwidjaya E, Kropp A, Peach HA, Carere CR, Stott MB, Schittenhelm RB, Greening C. Trace gas oxidation sustains energy needs of a thermophilic archaeon at suboptimal temperatures. Nat Commun 2024; 15:3219. [PMID: 38622143 PMCID: PMC11018855 DOI: 10.1038/s41467-024-47324-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/22/2024] [Indexed: 04/17/2024] Open
Abstract
Diverse aerobic bacteria use atmospheric hydrogen (H2) and carbon monoxide (CO) as energy sources to support growth and survival. Such trace gas oxidation is recognised as a globally significant process that serves as the main sink in the biogeochemical H2 cycle and sustains microbial biodiversity in oligotrophic ecosystems. However, it is unclear whether archaea can also use atmospheric H2. Here we show that a thermoacidophilic archaeon, Acidianus brierleyi (Thermoproteota), constitutively consumes H2 and CO to sub-atmospheric levels. Oxidation occurs across a wide range of temperatures (10 to 70 °C) and enhances ATP production during starvation-induced persistence under temperate conditions. The genome of A. brierleyi encodes a canonical CO dehydrogenase and four distinct [NiFe]-hydrogenases, which are differentially produced in response to electron donor and acceptor availability. Another archaeon, Metallosphaera sedula, can also oxidize atmospheric H2. Our results suggest that trace gas oxidation is a common trait of Sulfolobales archaea and may play a role in their survival and niche expansion, including during dispersal through temperate environments.
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Affiliation(s)
- Pok Man Leung
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.
| | - Rhys Grinter
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Eve Tudor-Matthew
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - James P Lingford
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Luis Jimenez
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Han-Chung Lee
- Monash Proteomics and Metabolomics Platform and Department of Biochemistry, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Michael Milton
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Iresha Hanchapola
- Monash Proteomics and Metabolomics Platform and Department of Biochemistry, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Erwin Tanuwidjaya
- Monash Proteomics and Metabolomics Platform and Department of Biochemistry, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Ashleigh Kropp
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Hanna A Peach
- Geomicrobiology Research Group, Department of Geothermal Sciences, Te Pū Ao | GNS Science, Wairakei, Taupō, 3377, Aotearoa New Zealand
| | - Carlo R Carere
- Geomicrobiology Research Group, Department of Geothermal Sciences, Te Pū Ao | GNS Science, Wairakei, Taupō, 3377, Aotearoa New Zealand
- Te Tari Pūhanga Tukanga Matū | Department of Chemical and Process Engineering, Te Whare Wānanga o Waitaha | University of Canterbury, Christchurch, 8140, Aotearoa New Zealand
| | - Matthew B Stott
- Geomicrobiology Research Group, Department of Geothermal Sciences, Te Pū Ao | GNS Science, Wairakei, Taupō, 3377, Aotearoa New Zealand
- Te Kura Pūtaiao Koiora | School of Biological Sciences, Te Whare Wānanga o Waitaha | University of Canterbury, Christchurch, 8140, Aotearoa New Zealand
| | - Ralf B Schittenhelm
- Monash Proteomics and Metabolomics Platform and Department of Biochemistry, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Chris Greening
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.
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2
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Kashani M, Engle MA, Kent DB, Gregston T, Cozzarelli IM, Mumford AC, Varonka MS, Harris CR, Akob DM. Illegal dumping of oil and gas wastewater alters arid soil microbial communities. Appl Environ Microbiol 2024; 90:e0149023. [PMID: 38294246 PMCID: PMC10880632 DOI: 10.1128/aem.01490-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 11/27/2023] [Indexed: 02/01/2024] Open
Abstract
The Permian Basin, underlying southeast New Mexico and west Texas, is one of the most productive oil and gas (OG) provinces in the United States. Oil and gas production yields large volumes of wastewater with complex chemistries, and the environmental health risks posed by these OG wastewaters on sensitive desert ecosystems are poorly understood. Starting in November 2017, 39 illegal dumps, as defined by federal and state regulations, of OG wastewater were identified in southeastern New Mexico, releasing ~600,000 L of fluid onto dryland soils. To evaluate the impacts of these releases, we analyzed changes in soil geochemistry and microbial community composition by comparing soils from within OG wastewater dump-affected samples to unaffected zones. We observed significant changes in soil geochemistry for all dump-affected compared with control samples, reflecting the residual salts and hydrocarbons from the OG-wastewater release (e.g., enriched in sodium, chloride, and bromide). Microbial community structure significantly (P < 0.01) differed between dump and control zones, with soils from dump areas having significantly (P < 0.01) lower alpha diversity and differences in phylogenetic composition. Dump-affected soil samples showed an increase in halophilic and halotolerant taxa, including members of the Marinobacteraceae, Halomonadaceae, and Halobacteroidaceae, suggesting that the high salinity of the dumped OG wastewater was exerting a strong selective pressure on microbial community structure. Taxa with high similarity to known hydrocarbon-degrading organisms were also detected in the dump-affected soil samples. Overall, this study demonstrates the potential for OG wastewater exposure to change the geochemistry and microbial community dynamics of arid soils.IMPORTANCEThe long-term environmental health impacts resulting from releases of oil and gas (OG) wastewater, typically brines with varying compositions of ions, hydrocarbons, and other constituents, are understudied. This is especially true for sensitive desert ecosystems, where soil microbes are key primary producers and drivers of nutrient cycling. We found that releases of OG wastewater can lead to shifts in microbial community composition and function toward salt- and hydrocarbon-tolerant taxa that are not typically found in desert soils, thus altering the impacted dryland soil ecosystem. Loss of key microbial taxa, such as those that catalyze organic carbon cycling, increase arid soil fertility, promote plant health, and affect soil moisture retention, could result in cascading effects across the sensitive desert ecosystem. By characterizing environmental changes due to releases of OG wastewater to soils overlying the Permian Basin, we gain further insights into how OG wastewater may alter dryland soil microbial functions and ecosystems.
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Affiliation(s)
- Mitra Kashani
- U.S. Geological Survey, Geology, Energy & Minerals Science Center, Reston, Virginia, USA
| | - Mark A Engle
- Department of Earth, Environmental and Resource Sciences, University of Texas at El Paso, El Paso, Texas, USA
| | - Douglas B Kent
- U.S. Geological Survey, Earth Systems Processes Division, Menlo Park, California, USA
| | | | - Isabelle M Cozzarelli
- U.S. Geological Survey, Geology, Energy & Minerals Science Center, Reston, Virginia, USA
| | - Adam C Mumford
- U.S. Geological Survey, Maryland-Delaware-D.C. Water Science Center, Baltimore, Maryland, USA
| | - Matthew S Varonka
- U.S. Geological Survey, Geology, Energy & Minerals Science Center, Reston, Virginia, USA
| | - Cassandra R Harris
- U.S. Geological Survey, Geology, Energy & Minerals Science Center, Reston, Virginia, USA
| | - Denise M Akob
- U.S. Geological Survey, Geology, Energy & Minerals Science Center, Reston, Virginia, USA
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3
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Garvin ZK, Abades SR, Trefault N, Alfaro FD, Sipes K, Lloyd KG, Onstott TC. Prevalence of trace gas-oxidizing soil bacteria increases with radial distance from Polloquere hot spring within a high-elevation Andean cold desert. THE ISME JOURNAL 2024; 18:wrae062. [PMID: 38625060 PMCID: PMC11094475 DOI: 10.1093/ismejo/wrae062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 01/29/2024] [Accepted: 04/10/2024] [Indexed: 04/17/2024]
Abstract
High-elevation arid regions harbor microbial communities reliant on metabolic niches and flexibility to survive under biologically stressful conditions, including nutrient limitation that necessitates the utilization of atmospheric trace gases as electron donors. Geothermal springs present "oases" of microbial activity, diversity, and abundance by delivering water and substrates, including reduced gases. However, it is unknown whether these springs exhibit a gradient of effects, increasing their impact on trace gas-oxidizers in the surrounding soils. We assessed whether proximity to Polloquere, a high-altitude geothermal spring in an Andean salt flat, alters the diversity and metabolic structure of nearby soil bacterial populations compared to the surrounding cold desert. Recovered DNA and metagenomic analyses indicate that the spring represents an oasis for microbes in this challenging environment, supporting greater biomass with more diverse metabolic functions in proximal soils that declines sharply with radial distance from the spring. Despite the sharp decrease in biomass, potential rates of atmospheric hydrogen (H2) and carbon monoxide (CO) uptake increase away from the spring. Kinetic estimates suggest this activity is due to high-affinity trace gas consumption, likely as a survival strategy for energy/carbon acquisition. These results demonstrate that Polloquere regulates a gradient of diverse microbial communities and metabolisms, culminating in increased activity of trace gas-oxidizers as the influence of the spring yields to that of the regional salt flat environment. This suggests the spring holds local importance within the context of the broader salt flat and potentially represents a model ecosystem for other geothermal systems in high-altitude desert environments.
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Affiliation(s)
- Zachary K Garvin
- Department of Geosciences, Princeton University, Princeton, NJ 08544, United States
| | - Sebastián R Abades
- GEMA Center for Genomics, Ecology and Environment, Faculty of Interdisciplinary Studies, Universidad Mayor, 8580745, Santiago, Chile
| | - Nicole Trefault
- GEMA Center for Genomics, Ecology and Environment, Faculty of Interdisciplinary Studies, Universidad Mayor, 8580745, Santiago, Chile
| | - Fernando D Alfaro
- GEMA Center for Genomics, Ecology and Environment, Faculty of Interdisciplinary Studies, Universidad Mayor, 8580745, Santiago, Chile
| | - Katie Sipes
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States
- Department of Environmental Science, Aarhus University, 4000, Roskilde, Denmark
| | - Karen G Lloyd
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States
| | - Tullis C Onstott
- Department of Geosciences, Princeton University, Princeton, NJ 08544, United States
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4
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Molecular hydrogen in seawater supports growth of diverse marine bacteria. Nat Microbiol 2023; 8:581-595. [PMID: 36747116 DOI: 10.1038/s41564-023-01322-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 01/05/2023] [Indexed: 02/08/2023]
Abstract
Molecular hydrogen (H2) is an abundant and readily accessible energy source in marine systems, but it remains unknown whether marine microbial communities consume this gas. Here we use a suite of approaches to show that marine bacteria consume H2 to support growth. Genes for H2-uptake hydrogenases are prevalent in global ocean metagenomes, highly expressed in metatranscriptomes and found across eight bacterial phyla. Capacity for H2 oxidation increases with depth and decreases with oxygen concentration, suggesting that H2 is important in environments with low primary production. Biogeochemical measurements of tropical, temperate and subantarctic waters, and axenic cultures show that marine microbes consume H2 supplied at environmentally relevant concentrations, yielding enough cell-specific power to support growth in bacteria with low energy requirements. Conversely, our results indicate that oxidation of carbon monoxide (CO) primarily supports survival. Altogether, H2 is a notable energy source for marine bacteria and may influence oceanic ecology and biogeochemistry.
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5
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Aidah N, Engeu OP, Baptist TJ, Muwanika VB, Johnson M, Joel B. Diversity of bacterial community in the rhizosphere and bulk soil of Artemisia annua grown in highlands of Uganda. PLoS One 2023; 18:e0269662. [PMID: 36952433 PMCID: PMC10035820 DOI: 10.1371/journal.pone.0269662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 05/26/2022] [Indexed: 03/25/2023] Open
Abstract
High land areas in Uganda are suitable for the farming of Artemisia annua. However, harvested A. annua from these areas contain varying concentrations of antimalarial components. This may be attributed to variation in soil properties which affect vegetative growth characters, yield and active compounds of A. annua. Thus, bacterial composition and physiochemical properties of soil from Kabale and Kabarole high land areas where A. annua is grown were studied. The study objective was to determine the diversity of bacterial community in the rhizosphere and bulk soil of A. annua grown in highlands of Uganda. Composition of bacterial community was analyzed by amplicon sequencing of 16S rRNA genes on an Illumina Miseq platform. A total of 1,420,688 read counts was obtained and clustered into 163,493 Operational Taxonomic Units ((OTU). Kabarole highland had more OTUs (87,229) than Kabale (76,264). The phylum Proteobacteria (34.2%) was the most prevalent followed by Acidobacteria (17.3%) and Actinobacteria (15.5%). The bacteria community in the two highlands significantly differed (p <0.05) among all phyla except Proteobacteria. The main genera in bulk soil were povalibacter, brevitalea, nocardioides, stenotrophobacter, gaiella and solirubrobacter. Sphingomonas, ramlibacter paludibaculum and pseudarthrobacter were the main genera in A. annua rhizospheric soil.
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Affiliation(s)
- Namuli Aidah
- Pharmbiotechnology and Traditional Medicine Center of Excellence, Mbarara University of Science and Technology, Mbarara, Uganda
- Department of Pharmacy, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Ogwang Patrick Engeu
- Pharmbiotechnology and Traditional Medicine Center of Excellence, Mbarara University of Science and Technology, Mbarara, Uganda
- Department of Pharmacy, Mbarara University of Science and Technology, Mbarara, Uganda
| | | | - Vincent B Muwanika
- Molecular Biology Laboratory Institute of Environment and Natural Resources, Makerere University, Kampala, Uganda
| | - Mayega Johnson
- Molecular Biology Laboratory Institute of Environment and Natural Resources, Makerere University, Kampala, Uganda
| | - Bazira Joel
- Pharmbiotechnology and Traditional Medicine Center of Excellence, Mbarara University of Science and Technology, Mbarara, Uganda
- Department of Microbiology, Mbarara University of Science and Technology, Mbarara, Uganda
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6
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Hogendoorn C, Pol A, de Graaf R, White PB, Mesman R, van Galen PM, van Alen TA, Cremers G, Jansen RS, Jetten MSM, Op den Camp HJM. " Candidatus Hydrogenisulfobacillus filiaventi" strain R50 gen. nov. sp. nov., a highly efficient producer of extracellular organic compounds from H 2 and CO 2. Front Microbiol 2023; 14:1151097. [PMID: 37032882 PMCID: PMC10080006 DOI: 10.3389/fmicb.2023.1151097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/08/2023] [Indexed: 04/11/2023] Open
Abstract
Production of organic molecules is largely depending on fossil fuels. A sustainable alternative would be the synthesis of these compounds from CO2 and a cheap energy source, such as H2, CH4, NH3, CO, sulfur compounds or iron(II). Volcanic and geothermal areas are rich in CO2 and reduced inorganic gasses and therefore habitats where novel chemolithoautotrophic microorganisms for the synthesis of organic compounds could be discovered. Here we describe "Candidatus Hydrogenisulfobacillus filiaventi" R50 gen. nov., sp. nov., a thermoacidophilic, autotrophic H2-oxidizing microorganism, that fixed CO2 and excreted no less than 0.54 mol organic carbon per mole fixed CO2. Extensive metabolomics and NMR analyses revealed that Val, Ala and Ile are the most dominant form of excreted organic carbon while the aromatic amino acids Tyr and Phe, and Glu and Lys were present at much lower concentrations. In addition to these proteinogenic amino acids, the excreted carbon consisted of homoserine lactone, homoserine and an unidentified amino acid. The biological role of the excretion remains uncertain. In the laboratory, we noticed the production under high growth rates (0.034 h-1, doubling time of 20 h) in combination with O2-limitation, which will most likely not occur in the natural habitat of this strain. Nevertheless, this large production of extracellular organic molecules from CO2 may open possibilities to use chemolithoautotrophic microorganisms for the sustainable production of important biomolecules.
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Affiliation(s)
- Carmen Hogendoorn
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Arjan Pol
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Rob de Graaf
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Paul B. White
- Department of Synthetic Organic Chemistry, IMM, Radboud University, Nijmegen, Netherlands
| | - Rob Mesman
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Peter M. van Galen
- Department of Systems Chemistry, IMM, Faculty of Science, Radboud University, Nijmegen, Netherlands
| | - Theo A. van Alen
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Geert Cremers
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Robert S. Jansen
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Mike S. M. Jetten
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Huub J. M. Op den Camp
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
- *Correspondence: Huub J. M. Op den Camp,
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7
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Leung PM, Daebeler A, Chiri E, Hanchapola I, Gillett DL, Schittenhelm RB, Daims H, Greening C. A nitrite-oxidising bacterium constitutively consumes atmospheric hydrogen. THE ISME JOURNAL 2022; 16:2213-2219. [PMID: 35752717 PMCID: PMC9381531 DOI: 10.1038/s41396-022-01265-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 05/27/2022] [Accepted: 06/07/2022] [Indexed: 11/08/2022]
Abstract
Chemolithoautotrophic nitrite-oxidising bacteria (NOB) of the genus Nitrospira contribute to nitrification in diverse natural environments and engineered systems. Nitrospira are thought to be well-adapted to substrate limitation owing to their high affinity for nitrite and capacity to use alternative energy sources. Here, we demonstrate that the canonical nitrite oxidiser Nitrospira moscoviensis oxidises hydrogen (H2) below atmospheric levels using a high-affinity group 2a nickel-iron hydrogenase [Km(app) = 32 nM]. Atmospheric H2 oxidation occurred under both nitrite-replete and nitrite-deplete conditions, suggesting low-potential electrons derived from H2 oxidation promote nitrite-dependent growth and enable survival during nitrite limitation. Proteomic analyses confirmed the hydrogenase was abundant under both conditions and indicated extensive metabolic changes occur to reduce energy expenditure and growth under nitrite-deplete conditions. Thermodynamic modelling revealed that H2 oxidation theoretically generates higher power yield than nitrite oxidation at low substrate concentrations and significantly contributes to growth at elevated nitrite concentrations. Collectively, this study suggests atmospheric H2 oxidation enhances the growth and survival of NOB amid variability of nitrite supply, extends the phenomenon of atmospheric H2 oxidation to an eighth phylum (Nitrospirota), and reveals unexpected new links between the global hydrogen and nitrogen cycles. Long classified as obligate nitrite oxidisers, our findings suggest H2 may primarily support growth and survival of certain NOB in natural environments.
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Affiliation(s)
- Pok Man Leung
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Anne Daebeler
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
- Soil and Water Research Infrastructure, Biology Centre CAS, Budweis, Czechia.
| | - Eleonora Chiri
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Iresha Hanchapola
- Monash Proteomics and Metabolomics Facility and Department of Biochemistry, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - David L Gillett
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Ralf B Schittenhelm
- Monash Proteomics and Metabolomics Facility and Department of Biochemistry, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Holger Daims
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
- University of Vienna, The Comammox Research Platform, Vienna, Austria.
| | - Chris Greening
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.
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8
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Paracidobacterium acidisoli gen. nov., sp. nov. and Alloacidobacterium dinghuense gen. nov., sp. nov., two acidobacteria isolated from forest soil, and reclassification of Acidobacterium ailaaui and Acidipila dinghuensis as Pseudacidobacterium ailaaui gen. nov., comb. nov. and Silvibacterium dinghuense comb. nov. Int J Syst Evol Microbiol 2022; 72. [DOI: 10.1099/ijsem.0.005415] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two aerobic and obligately acidophilic bacteria, designated 4G-K13T and 4Y35T, were isolated from the forest soil sampled at Dinghushan Biosphere Reserve, Guangdong Province, PR China. These two strains were Gram-stain-negative, non-motile and short rods that multiplied by binary division. Strains 4G-K13T and 4Y35T had the highest 16S rRNA gene sequence similarity of 97.0 and 97.2 % to
Silvibacterium bohemicum
DSM 103733T and
Acidisarcina polymorpha
SBC82T, respectively. Phylogenetic trees based on the 16S rRNA gene and whole genome sequences showed consistently that these two strains formed a major clade with members of the genera
Acidipila
,
Acidisarcina
,
Silvibacterium
and
Acidobacterium
in the family
Acidobacteriaceae
, but each occupied an unique position. In both the UBCG and the PhyloPhlAn phylogenomic trees, strains 4G-K13T and 4Y35T congruently formed a highly supported subclade with
Acidobacterium capsulatum
DSM 11244T and
Acidobacterium ailaaui
DSM 27394T, respectively. The major fatty acids (>5 %) of strain 4G-K13T were iso-C15 : 0, iso-C17 : 0, summed feature 3 (C16 : 1
ω7c and/or C16 : 1
ω6c) and summed feature 9 (iso-C17 : 1
ω9c and/or C16 : 0 10-methyl), while that of strain 4Y35T were C16 : 0, C18 : 1
ω9c, iso-C15 : 0, summed feature 3 (C16 : 1
ω7c and/or C16 : 1
ω6c) and summed feature 9 (iso-C17 : 1
ω9c and/or C16 : 0 10-methyl). Strain 4G-K13T contained phosphatidylethanolamine, four unidentified phospholipids, four glycolipids, two unidentified aminolipids and two unknown lipids, while strain 4Y35T had phosphatidylethanolamine, three unidentified phospholipids, two glycolipids, five unidentified aminolipids and one unknown polar lipid. The DNA G+C contents of 4G-K13T and 4Y35T were 60.5 and 55.8 mol%, respectively. Based on all these phylogenetic, physiological and chemotaxonomic data, we suggest that strains 4G-K13T and 4Y35T represent two novel species of two novel genera in the family
Acidobacteriaceae
, for which the names Paracidobacterium acidisoli gen. nov., sp. nov. (type strain: 4G-K13T=GDMCC 1.1195T=NBRC 113249T) and Alloacidobacterium dinghuense gen. nov., sp. nov. (type strain: 4Y35T=KACC 21728T=NBRC 114261T) are proposed. We also propose to reclassify
Acidobacterium ailaaui
and
Acidipila dinghuensis
as Pseudacidobacterium ailaaui gen. nov., comb. nov. and Silvibacterium dinghuense comb. nov., respectively, based mainly on the results of phylogenomic analysis.
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9
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Greening C, Grinter R. Microbial oxidation of atmospheric trace gases. Nat Rev Microbiol 2022; 20:513-528. [PMID: 35414013 DOI: 10.1038/s41579-022-00724-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2022] [Indexed: 02/06/2023]
Abstract
The atmosphere has recently been recognized as a major source of energy sustaining life. Diverse aerobic bacteria oxidize the three most abundant reduced trace gases in the atmosphere, namely hydrogen (H2), carbon monoxide (CO) and methane (CH4). This Review describes the taxonomic distribution, physiological role and biochemical basis of microbial oxidation of these atmospheric trace gases, as well as the ecological, environmental, medical and astrobiological importance of this process. Most soil bacteria and some archaea can survive by using atmospheric H2 and CO as alternative energy sources, as illustrated through genetic studies on Mycobacterium cells and Streptomyces spores. Certain specialist bacteria can also grow on air alone, as confirmed by the landmark characterization of Methylocapsa gorgona, which grows by simultaneously consuming atmospheric CH4, H2 and CO. Bacteria use high-affinity lineages of metalloenzymes, namely hydrogenases, CO dehydrogenases and methane monooxygenases, to utilize atmospheric trace gases for aerobic respiration and carbon fixation. More broadly, trace gas oxidizers enhance the biodiversity and resilience of soil and marine ecosystems, drive primary productivity in extreme environments such as Antarctic desert soils and perform critical regulatory services by mitigating anthropogenic emissions of greenhouse gases and toxic pollutants.
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Affiliation(s)
- Chris Greening
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia. .,Securing Antarctica's Environmental Future, Monash University, Clayton, Victoria, Australia. .,Centre to Impact AMR, Monash University, Clayton, Victoria, Australia.
| | - Rhys Grinter
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.
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10
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Wang G, Li Y, Liu J, Chen B, Su H, Liang J, Huang W, Yu K. Comparative Genomics Reveal the Animal-Associated Features of the Acanthopleuribacteraceae Bacteria, and Description of Sulfidibacter corallicola gen. nov., sp., nov. Front Microbiol 2022; 13:778535. [PMID: 35173698 PMCID: PMC8841776 DOI: 10.3389/fmicb.2022.778535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 01/07/2022] [Indexed: 11/13/2022] Open
Abstract
Members of the phylum Acidobacteria are ubiquitous in various environments. Soil acidobacteria have been reported to present a variety of strategies for their success in terrestrial environments. However, owing to lack of pure culture, information on animal-associated acidobacteria are limited, except for those obtained from 16S rRNA genes. To date, only two acidobacteria have been isolated from animals, namely strain M133T obtained from coral Porites lutea and Acanthopleuribacter pedis KCTC 12899T isolated from chiton. Genomics and physiological characteristics of strain M133T and A. pedis KCTC 12899T were compared with 19 other isolates (one strain from each genus) in the phylum Acidobacteria. The results revealed that strain M133T represents a new species in a new genus in the family Acanthopleuribacteraceae. To date, these two Acanthopleuribacteraceae isolates have the largest genomes (10.85–11.79 Mb) in the phylum Acidobacteria. Horizontal gene transfer and gene duplication influenced the structure and plasticity of these large genomes. Dissimilatory nitrate reduction and abundant secondary metabolite biosynthetic gene clusters (including eicosapentaenoic acid de novo biosynthesis) are two distinct features of the Acanthopleuribacteraceae bacteria in the phylum Acidobacteria. The absence of glycoside hydrolases involved in plant polysaccharide degradation and presence of animal disease-related peptidases indicate that these bacteria have evolved to adapt to the animal hosts. In addition to low- and high-affinity respiratory oxygen reductases, enzymes for nitrate to nitrogen, and sulfhydrogenase were also detected in strain M133T, suggesting the capacity and flexibility to grow in aerobic and anaerobic environments. This study highlighted the differences in genome structure, carbohydrate and protein utilization, respiration, and secondary metabolism between animal-associated acidobacteria and other acidobacteria, especially the soil acidobacteria, displaying flexibility and versatility of the animal-associated acidobacteria in environmental adaption.
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Affiliation(s)
- Guanghua Wang
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, China
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Yuanjin Li
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, China
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Jianfeng Liu
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, China
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Biao Chen
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, China
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Hongfei Su
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, China
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Jiayuan Liang
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, China
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Wen Huang
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, China
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Kefu Yu
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning, China
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
- *Correspondence: Kefu Yu,
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11
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Multiple energy sources and metabolic strategies sustain microbial diversity in Antarctic desert soils. Proc Natl Acad Sci U S A 2021; 118:2025322118. [PMID: 34732568 DOI: 10.1073/pnas.2025322118] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2021] [Indexed: 12/11/2022] Open
Abstract
Numerous diverse microorganisms reside in the cold desert soils of continental Antarctica, though we lack a holistic understanding of the metabolic processes that sustain them. Here, we profile the composition, capabilities, and activities of the microbial communities in 16 physicochemically diverse mountainous and glacial soils. We assembled 451 metagenome-assembled genomes from 18 microbial phyla and inferred through Bayesian divergence analysis that the dominant lineages present are likely native to Antarctica. In support of earlier findings, metagenomic analysis revealed that the most abundant and prevalent microorganisms are metabolically versatile aerobes that use atmospheric hydrogen to support aerobic respiration and sometimes carbon fixation. Surprisingly, however, hydrogen oxidation in this region was catalyzed primarily by a phylogenetically and structurally distinct enzyme, the group 1l [NiFe]-hydrogenase, encoded by nine bacterial phyla. Through gas chromatography, we provide evidence that both Antarctic soil communities and an axenic Bacteroidota isolate (Hymenobacter roseosalivarius) oxidize atmospheric hydrogen using this enzyme. Based on ex situ rates at environmentally representative temperatures, hydrogen oxidation is theoretically sufficient for soil communities to meet energy requirements and, through metabolic water production, sustain hydration. Diverse carbon monoxide oxidizers and abundant methanotrophs were also active in the soils. We also recovered genomes of microorganisms capable of oxidizing edaphic inorganic nitrogen, sulfur, and iron compounds and harvesting solar energy via microbial rhodopsins and conventional photosystems. Obligately symbiotic bacteria, including Patescibacteria, Chlamydiae, and predatory Bdellovibrionota, were also present. We conclude that microbial diversity in Antarctic soils reflects the coexistence of metabolically flexible mixotrophs with metabolically constrained specialists.
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12
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Bay SK, Waite DW, Dong X, Gillor O, Chown SL, Hugenholtz P, Greening C. Chemosynthetic and photosynthetic bacteria contribute differentially to primary production across a steep desert aridity gradient. THE ISME JOURNAL 2021; 15:3339-3356. [PMID: 34035443 PMCID: PMC8528921 DOI: 10.1038/s41396-021-01001-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 04/16/2021] [Accepted: 04/28/2021] [Indexed: 02/04/2023]
Abstract
Desert soils harbour diverse communities of aerobic bacteria despite lacking substantial organic carbon inputs from vegetation. A major question is therefore how these communities maintain their biodiversity and biomass in these resource-limiting ecosystems. Here, we investigated desert topsoils and biological soil crusts collected along an aridity gradient traversing four climatic regions (sub-humid, semi-arid, arid, and hyper-arid). Metagenomic analysis indicated these communities vary in their capacity to use sunlight, organic compounds, and inorganic compounds as energy sources. Thermoleophilia, Actinobacteria, and Acidimicrobiia were the most abundant and prevalent bacterial classes across the aridity gradient in both topsoils and biocrusts. Contrary to the classical view that these taxa are obligate organoheterotrophs, genome-resolved analysis suggested they are metabolically flexible, with the capacity to also use atmospheric H2 to support aerobic respiration and often carbon fixation. In contrast, Cyanobacteria were patchily distributed and only abundant in certain biocrusts. Activity measurements profiled how aerobic H2 oxidation, chemosynthetic CO2 fixation, and photosynthesis varied with aridity. Cell-specific rates of atmospheric H2 consumption increased 143-fold along the aridity gradient, correlating with increased abundance of high-affinity hydrogenases. Photosynthetic and chemosynthetic primary production co-occurred throughout the gradient, with photosynthesis dominant in biocrusts and chemosynthesis dominant in arid and hyper-arid soils. Altogether, these findings suggest that the major bacterial lineages inhabiting hot deserts use different strategies for energy and carbon acquisition depending on resource availability. Moreover, they highlight the previously overlooked roles of Actinobacteriota as abundant primary producers and trace gases as critical energy sources supporting productivity and resilience of desert ecosystems.
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Affiliation(s)
- Sean K Bay
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.
- School of Biological Sciences, Monash University, Clayton, VIC, Australia.
| | - David W Waite
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Xiyang Dong
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai, China
| | - Osnat Gillor
- Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Sde Boker, Israel
| | - Steven L Chown
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
| | - Chris Greening
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.
- School of Biological Sciences, Monash University, Clayton, VIC, Australia.
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13
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Candidatus Eremiobacterota, a metabolically and phylogenetically diverse terrestrial phylum with acid-tolerant adaptations. THE ISME JOURNAL 2021; 15:2692-2707. [PMID: 33753881 PMCID: PMC8397712 DOI: 10.1038/s41396-021-00944-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 02/11/2021] [Accepted: 02/18/2021] [Indexed: 02/01/2023]
Abstract
Candidatus phylum Eremiobacterota (formerly WPS-2) is an as-yet-uncultured bacterial clade that takes its name from Ca. Eremiobacter, an Antarctic soil aerobe proposed to be capable of a novel form of chemolithoautotrophy termed atmospheric chemosynthesis, that uses the energy derived from atmospheric H2-oxidation to fix CO2 through the Calvin-Benson-Bassham (CBB) cycle via type 1E RuBisCO. To elucidate the phylogenetic affiliation and metabolic capacities of Ca. Eremiobacterota, we analysed 63 public metagenome-assembled genomes (MAGs) and nine new MAGs generated from Antarctic soil metagenomes. These MAGs represent both recognized classes within Ca. Eremiobacterota, namely Ca. Eremiobacteria and UBP9. Ca. Eremiobacteria are inferred to be facultatively acidophilic with a preference for peptides and amino acids as nutrient sources. Epifluorescence microscopy revealed Ca. Eremiobacteria cells from Antarctica desert soil to be coccoid in shape. Two orders are recognized within class Ca. Eremiobacteria: Ca. Eremiobacterales and Ca. Baltobacterales. The latter are metabolically versatile, with individual members having genes required for trace gas driven autotrophy, anoxygenic photosynthesis, CO oxidation, and anaerobic respiration. UBP9, here renamed Ca. Xenobia class. nov., are inferred to be obligate heterotrophs with acidophilic adaptations, but individual members having highly divergent metabolic capacities compared to Ca. Eremiobacteria, especially with regard to respiration and central carbon metabolism. We conclude Ca. Eremiobacterota to be an ecologically versatile phylum with the potential to thrive under an array of "extreme" environmental conditions.
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14
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Greening C, Islam ZF, Bay SK. Hydrogen is a major lifeline for aerobic bacteria. Trends Microbiol 2021; 30:330-337. [PMID: 34462186 DOI: 10.1016/j.tim.2021.08.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/06/2021] [Accepted: 08/09/2021] [Indexed: 12/31/2022]
Abstract
Molecular hydrogen (H2) is available in trace amounts in most ecosystems through atmospheric, biological, geochemical, and anthropogenic sources. Aerobic bacteria use this energy-dense gas, including at atmospheric concentrations, to support respiration and carbon fixation. While it was thought that aerobic H2 consumers are rare community members, here we summarize evidence suggesting that they are dominant throughout soils and other aerated ecosystems. Bacterial cultures from at least eight major phyla can consume atmospheric H2. At the ecosystem scale, H2 consumers are abundant, diverse, and active across diverse soils and are key primary producers in extreme environments such as hyper-arid deserts. On this basis, we propose that H2 is a universally available energy source for the survival of aerobic bacteria.
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Affiliation(s)
- Chris Greening
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Securing Antarctica's Environmental Future, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia.
| | - Zahra F Islam
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; STEM College, RMIT University, Bundoora, VIC 3083, Australia
| | - Sean K Bay
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Securing Antarctica's Environmental Future, Monash University, Clayton, VIC 3800, Australia; School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
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15
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Trace gas oxidizers are widespread and active members of soil microbial communities. Nat Microbiol 2021; 6:246-256. [PMID: 33398096 DOI: 10.1038/s41564-020-00811-w] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 10/08/2020] [Indexed: 01/24/2023]
Abstract
Soil microorganisms globally are thought to be sustained primarily by organic carbon sources. Certain bacteria also consume inorganic energy sources such as trace gases, but they are presumed to be rare community members, except within some oligotrophic soils. Here we combined metagenomic, biogeochemical and modelling approaches to determine how soil microbial communities meet energy and carbon needs. Analysis of 40 metagenomes and 757 derived genomes indicated that over 70% of soil bacterial taxa encode enzymes to consume inorganic energy sources. Bacteria from 19 phyla encoded enzymes to use the trace gases hydrogen and carbon monoxide as supplemental electron donors for aerobic respiration. In addition, we identified a fourth phylum (Gemmatimonadota) potentially capable of aerobic methanotrophy. Consistent with the metagenomic profiling, communities within soil profiles from diverse habitats rapidly oxidized hydrogen, carbon monoxide and to a lesser extent methane below atmospheric concentrations. Thermodynamic modelling indicated that the power generated by oxidation of these three gases is sufficient to meet the maintenance needs of the bacterial cells capable of consuming them. Diverse bacteria also encode enzymes to use trace gases as electron donors to support carbon fixation. Altogether, these findings indicate that trace gas oxidation confers a major selective advantage in soil ecosystems, where availability of preferred organic substrates limits microbial growth. The observation that inorganic energy sources may sustain most soil bacteria also has broad implications for understanding atmospheric chemistry and microbial biodiversity in a changing world.
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16
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Jordaan K, Lappan R, Dong X, Aitkenhead IJ, Bay SK, Chiri E, Wieler N, Meredith LK, Cowan DA, Chown SL, Greening C. Hydrogen-Oxidizing Bacteria Are Abundant in Desert Soils and Strongly Stimulated by Hydration. mSystems 2020; 5:e01131-20. [PMID: 33203691 PMCID: PMC7677003 DOI: 10.1128/msystems.01131-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 10/29/2020] [Indexed: 01/19/2023] Open
Abstract
How the diverse bacterial communities inhabiting desert soils maintain energy and carbon needs is much debated. Traditionally, most bacteria are thought to persist by using organic carbon synthesized by photoautotrophs following transient hydration events. Recent studies focused on Antarctic desert soils have revealed, however, that some bacteria use atmospheric trace gases, such as hydrogen (H2), to conserve energy and fix carbon independently of photosynthesis. In this study, we investigated whether atmospheric H2 oxidation occurs in four nonpolar desert soils and compared this process to photosynthesis. To do so, we first profiled the distribution, expression, and activities of hydrogenases and photosystems in surface soils collected from the South Australian desert over a simulated hydration-desiccation cycle. Hydrogenase-encoding sequences were abundant in the metagenomes and metatranscriptomes and were detected in actinobacterial, acidobacterial, and cyanobacterial metagenome-assembled genomes. Native dry soil samples mediated H2 oxidation, but rates increased 950-fold following wetting. Oxygenic and anoxygenic phototrophs were also detected in the community but at lower abundances. Hydration significantly stimulated rates of photosynthetic carbon fixation and, to a lesser extent, dark carbon assimilation. Hydrogenase genes were also widespread in samples from three other climatically distinct deserts, the Namib, Gobi, and Mojave, and atmospheric H2 oxidation was also greatly stimulated by hydration at these sites. Together, these findings highlight that H2 is an important, hitherto-overlooked energy source supporting bacterial communities in desert soils. Contrary to our previous hypotheses, however, H2 oxidation occurs simultaneously rather than alternately with photosynthesis in such ecosystems and may even be mediated by some photoautotrophs.IMPORTANCE Desert ecosystems, spanning a third of the earth's surface, harbor remarkably diverse microbial life despite having a low potential for photosynthesis. In this work, we reveal that atmospheric hydrogen serves as a major previously overlooked energy source for a large proportion of desert bacteria. We show that both chemoheterotrophic and photoautotrophic bacteria have the potential to oxidize hydrogen across deserts sampled across four continents. Whereas hydrogen oxidation was slow in native dry deserts, it increased by three orders of magnitude together with photosynthesis following hydration. This study revealed that continual harvesting of atmospheric energy sources may be a major way that desert communities adapt to long periods of water and energy deprivation, with significant ecological and biogeochemical ramifications.
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Affiliation(s)
- Karen Jordaan
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Rachael Lappan
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Xiyang Dong
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai, China
| | - Ian J Aitkenhead
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
| | - Sean K Bay
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Eleonora Chiri
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | | | - Laura K Meredith
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona, USA
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Steven L Chown
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
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17
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Oberpaul M, Zumkeller CM, Culver T, Spohn M, Mihajlovic S, Leis B, Glaeser SP, Plarre R, McMahon DP, Hammann P, Schäberle TF, Glaeser J, Vilcinskas A. High-Throughput Cultivation for the Selective Isolation of Acidobacteria From Termite Nests. Front Microbiol 2020; 11:597628. [PMID: 33240253 PMCID: PMC7677567 DOI: 10.3389/fmicb.2020.597628] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/19/2020] [Indexed: 12/27/2022] Open
Abstract
Microbial communities in the immediate environment of socialized invertebrates can help to suppress pathogens, in part by synthesizing bioactive natural products. Here we characterized the core microbiomes of three termite species (genus Coptotermes) and their nest material to gain more insight into the diversity of termite-associated bacteria. Sampling a healthy termite colony over time implicated a consolidated and highly stable microbiome, pointing toward the fact that beneficial bacterial phyla play a major role in termite fitness. In contrast, there was a significant shift in the composition of the core microbiome in one nest during a fungal infection, affecting the abundance of well-characterized Streptomyces species (phylum Actinobacteria) as well as less-studied bacterial phyla such as Acidobacteria. High-throughput cultivation in microplates was implemented to isolate and identify these less-studied bacterial phylogenetic group. Amplicon sequencing confirmed that our method maintained the bacterial diversity of the environmental samples, enabling the isolation of novel Acidobacteriaceae and expanding the list of cultivated species to include two strains that may define new species within the genera Terracidiphilus and Acidobacterium.
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Affiliation(s)
- Markus Oberpaul
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Giessen, Germany
| | - Celine M. Zumkeller
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Giessen, Germany
| | - Tanja Culver
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Giessen, Germany
| | - Marius Spohn
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Giessen, Germany
| | - Sanja Mihajlovic
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Giessen, Germany
| | - Benedikt Leis
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Giessen, Germany
| | - Stefanie P. Glaeser
- Institute of Applied Microbiology, Justus Liebig University Giessen, Giessen, Germany
| | - Rudy Plarre
- Bundesanstalt für Materialforschung und -prüfung, Berlin, Germany
| | - Dino P. McMahon
- Bundesanstalt für Materialforschung und -prüfung, Berlin, Germany
- Institute of Biology, Free University of Berlin, Berlin, Germany
| | - Peter Hammann
- Sanofi-Aventis Deutschland GmbH, R&D Integrated Drug Discovery, Hoechst Industrial Park, Frankfurt am Main, Germany
| | - Till F. Schäberle
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Giessen, Germany
- Institute for Insect Biotechnology, Justus Liebig University Giessen, Giessen, Germany
| | - Jens Glaeser
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Giessen, Germany
| | - Andreas Vilcinskas
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Giessen, Germany
- Institute for Insect Biotechnology, Justus Liebig University Giessen, Giessen, Germany
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18
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Kalam S, Basu A, Ahmad I, Sayyed RZ, El-Enshasy HA, Dailin DJ, Suriani NL. Recent Understanding of Soil Acidobacteria and Their Ecological Significance: A Critical Review. Front Microbiol 2020; 11:580024. [PMID: 33193209 PMCID: PMC7661733 DOI: 10.3389/fmicb.2020.580024] [Citation(s) in RCA: 196] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 10/08/2020] [Indexed: 11/13/2022] Open
Abstract
Acidobacteria represents an underrepresented soil bacterial phylum whose members are pervasive and copiously distributed across nearly all ecosystems. Acidobacterial sequences are abundant in soils and represent a significant fraction of soil microbial community. Being recalcitrant and difficult-to-cultivate under laboratory conditions, holistic, polyphasic approaches are required to study these refractive bacteria extensively. Acidobacteria possesses an inventory of genes involved in diverse metabolic pathways, as evidenced by their pan-genomic profiles. Because of their preponderance and ubiquity in the soil, speculations have been made regarding their dynamic roles in vital ecological processes viz., regulation of biogeochemical cycles, decomposition of biopolymers, exopolysaccharide secretion, and plant growth promotion. These bacteria are expected to have genes that might help in survival and competitive colonization in the rhizosphere, leading to the establishment of beneficial relationships with plants. Exploration of these genetic attributes and more in-depth insights into the belowground mechanics and dynamics would lead to a better understanding of the functions and ecological significance of this enigmatic phylum in the soil-plant environment. This review is an effort to provide a recent update into the diversity of genes in Acidobacteria useful for characterization, understanding ecological roles, and future biotechnological perspectives.
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Affiliation(s)
- Sadaf Kalam
- Department of Biochemistry, St. Ann's College for Women, Hyderabad, India
| | - Anirban Basu
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Iqbal Ahmad
- Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, India
| | - R Z Sayyed
- Department of Microbiology, PSGVP Mandal's, Arts, Science and Commerce College, Shahada, India
| | - Hesham Ali El-Enshasy
- Institute of Bioproduct Development, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia.,School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia.,City of Scientific Research and Technological Applications, New Borg El-Arab, Egypt
| | - Daniel Joe Dailin
- Institute of Bioproduct Development, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia.,School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia
| | - Ni Luh Suriani
- Biology Department, Faculty of Mathematics and Natural Science, Udayana University, Bali, Indonesia
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19
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Giguere AT, Eichorst SA, Meier DV, Herbold CW, Richter A, Greening C, Woebken D. Acidobacteria are active and abundant members of diverse atmospheric H 2-oxidizing communities detected in temperate soils. ISME JOURNAL 2020; 15:363-376. [PMID: 33024291 PMCID: PMC8027828 DOI: 10.1038/s41396-020-00750-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/30/2020] [Accepted: 08/12/2020] [Indexed: 12/24/2022]
Abstract
Significant rates of atmospheric dihydrogen (H2) consumption have been observed in temperate soils due to the activity of high-affinity enzymes, such as the group 1h [NiFe]-hydrogenase. We designed broadly inclusive primers targeting the large subunit gene (hhyL) of group 1h [NiFe]-hydrogenases for long-read sequencing to explore its taxonomic distribution across soils. This approach revealed a diverse collection of microorganisms harboring hhyL, including previously unknown groups and taxonomically not assignable sequences. Acidobacterial group 1h [NiFe]-hydrogenase genes were abundant and expressed in temperate soils. To support the participation of acidobacteria in H2 consumption, we studied two representative mesophilic soil acidobacteria, which expressed group 1h [NiFe]-hydrogenases and consumed atmospheric H2 during carbon starvation. This is the first time mesophilic acidobacteria, which are abundant in ubiquitous temperate soils, have been shown to oxidize H2 down to below atmospheric concentrations. As this physiology allows bacteria to survive periods of carbon starvation, it could explain the success of soil acidobacteria. With our long-read sequencing approach of group 1h [NiFe]-hydrogenase genes, we show that the ability to oxidize atmospheric levels of H2 is more widely distributed among soil bacteria than previously recognized and could represent a common mechanism enabling bacteria to persist during periods of carbon deprivation.
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Affiliation(s)
- Andrew T Giguere
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.,Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Stephanie A Eichorst
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
| | - Dimitri V Meier
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Craig W Herbold
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Andreas Richter
- Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Chris Greening
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.,School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Dagmar Woebken
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
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20
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A widely distributed hydrogenase oxidises atmospheric H 2 during bacterial growth. ISME JOURNAL 2020; 14:2649-2658. [PMID: 32647310 PMCID: PMC7784904 DOI: 10.1038/s41396-020-0713-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/25/2020] [Accepted: 06/30/2020] [Indexed: 11/09/2022]
Abstract
Diverse aerobic bacteria persist by consuming atmospheric hydrogen (H2) using group 1h [NiFe]-hydrogenases. However, other hydrogenase classes are also distributed in aerobes, including the group 2a [NiFe]-hydrogenase. Based on studies focused on Cyanobacteria, the reported physiological role of the group 2a [NiFe]-hydrogenase is to recycle H2 produced by nitrogenase. However, given this hydrogenase is also present in various heterotrophs and lithoautotrophs lacking nitrogenases, it may play a wider role in bacterial metabolism. Here we investigated the role of this enzyme in three species from different phylogenetic lineages and ecological niches: Acidithiobacillus ferrooxidans (phylum Proteobacteria), Chloroflexus aggregans (phylum Chloroflexota), and Gemmatimonas aurantiaca (phylum Gemmatimonadota). qRT-PCR analysis revealed that the group 2a [NiFe]-hydrogenase of all three species is significantly upregulated during exponential growth compared to stationary phase, in contrast to the profile of the persistence-linked group 1h [NiFe]-hydrogenase. Whole-cell biochemical assays confirmed that all three strains aerobically respire H2 to sub-atmospheric levels, and oxidation rates were much higher during growth. Moreover, the oxidation of H2 supported mixotrophic growth of the carbon-fixing strains C. aggregans and A. ferrooxidans. Finally, we used phylogenomic analyses to show that this hydrogenase is widely distributed and is encoded by 13 bacterial phyla. These findings challenge the current persistence-centric model of the physiological role of atmospheric H2 oxidation and extend this process to two more phyla, Proteobacteria and Gemmatimonadota. In turn, these findings have broader relevance for understanding how bacteria conserve energy in different environments and control the biogeochemical cycling of atmospheric trace gases.
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Hogendoorn C, Pol A, Picone N, Cremers G, van Alen TA, Gagliano AL, Jetten MSM, D'Alessandro W, Quatrini P, Op den Camp HJM. Hydrogen and Carbon Monoxide-Utilizing Kyrpidia spormannii Species From Pantelleria Island, Italy. Front Microbiol 2020; 11:951. [PMID: 32508778 PMCID: PMC7248562 DOI: 10.3389/fmicb.2020.00951] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 04/21/2020] [Indexed: 02/04/2023] Open
Abstract
Volcanic and geothermal areas are hot and often acidic environments that emit geothermal gasses, including H2, CO and CO2. Geothermal gasses mix with air, creating conditions where thermoacidophilic aerobic H2- and CO-oxidizing microorganisms could thrive. Here, we describe the isolation of two Kyrpidia spormannii strains, which can grow autotrophically by oxidizing H2 and CO with oxygen. These strains, FAVT5 and COOX1, were isolated from the geothermal soils of the Favara Grande on Pantelleria Island, Italy. Extended physiology studies were performed with K. spormannii FAVT5, and showed that this strain grows optimally at 55°C and pH 5.0. The highest growth rate is obtained using H2 as energy source (μmax 0.19 ± 0.02 h–1, doubling time 3.6 h). K. spormannii FAVT5 can additionally grow on a variety of organic substrates, including some alcohols, volatile fatty acids and amino acids. The genome of each strain encodes for two O2-tolerant hydrogenases belonging to [NiFe] group 2a hydrogenases and transcriptome studies using K. spormannii FAVT5 showed that both hydrogenases are expressed under H2 limiting conditions. So far no Firmicutes except K. spormannii FAVT5 have been reported to exhibit a high affinity for H2, with a Ks of 327 ± 24 nM. The genomes of each strain encode for one putative CO dehydrogenase, belonging to Form II aerobic CO dehydrogenases. The genomic potential and physiological properties of these Kyrpidia strains seem to be quite well adapted to thrive in the harsh environmental volcanic conditions.
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Affiliation(s)
- Carmen Hogendoorn
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
| | - Arjan Pol
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
| | - Nunzia Picone
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
| | - Geert Cremers
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
| | - Theo A van Alen
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
| | | | - Mike S M Jetten
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
| | | | - Paola Quatrini
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Palermo, Italy
| | - Huub J M Op den Camp
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
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22
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Leung PM, Bay SK, Meier DV, Chiri E, Cowan DA, Gillor O, Woebken D, Greening C. Energetic Basis of Microbial Growth and Persistence in Desert Ecosystems. mSystems 2020; 5:e00495-19. [PMID: 32291352 PMCID: PMC7159902 DOI: 10.1128/msystems.00495-19] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial life is surprisingly abundant and diverse in global desert ecosystems. In these environments, microorganisms endure a multitude of physicochemical stresses, including low water potential, carbon and nitrogen starvation, and extreme temperatures. In this review, we summarize our current understanding of the energetic mechanisms and trophic dynamics that underpin microbial function in desert ecosystems. Accumulating evidence suggests that dormancy is a common strategy that facilitates microbial survival in response to water and carbon limitation. Whereas photoautotrophs are restricted to specific niches in extreme deserts, metabolically versatile heterotrophs persist even in the hyper-arid topsoils of the Atacama Desert and Antarctica. At least three distinct strategies appear to allow such microorganisms to conserve energy in these oligotrophic environments: degradation of organic energy reserves, rhodopsin- and bacteriochlorophyll-dependent light harvesting, and oxidation of the atmospheric trace gases hydrogen and carbon monoxide. In turn, these principles are relevant for understanding the composition, functionality, and resilience of desert ecosystems, as well as predicting responses to the growing problem of desertification.
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Affiliation(s)
- Pok Man Leung
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Sean K Bay
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Dimitri V Meier
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Eleonora Chiri
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, University of Pretoria, Hatfield, Pretoria, South Africa
| | - Osnat Gillor
- Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Sde Boker, Israel
| | - Dagmar Woebken
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
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23
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Tan W, Liao TH, Wang J, Ye Y, Wei YC, Zhou HK, Xiao Y, Zhi XY, Shao ZH, Lyu LD, Zhao GP. A recently evolved diflavin-containing monomeric nitrate reductase is responsible for highly efficient bacterial nitrate assimilation. J Biol Chem 2020; 295:5051-5066. [PMID: 32111737 DOI: 10.1074/jbc.ra120.012859] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/25/2020] [Indexed: 12/11/2022] Open
Abstract
Nitrate is one of the major inorganic nitrogen sources for microbes. Many bacterial and archaeal lineages have the capacity to express assimilatory nitrate reductase (NAS), which catalyzes the rate-limiting reduction of nitrate to nitrite. Although a nitrate assimilatory pathway in mycobacteria has been proposed and validated physiologically and genetically, the putative NAS enzyme has yet to be identified. Here, we report the characterization of a novel NAS encoded by Mycolicibacterium smegmatis Msmeg_4206, designated NasN, which differs from the canonical NASs in its structure, electron transfer mechanism, enzymatic properties, and phylogenetic distribution. Using sequence analysis and biochemical characterization, we found that NasN is an NADPH-dependent, diflavin-containing monomeric enzyme composed of a canonical molybdopterin cofactor-binding catalytic domain and an FMN-FAD/NAD-binding, electron-receiving/transferring domain, making it unique among all previously reported hetero-oligomeric NASs. Genetic studies revealed that NasN is essential for aerobic M. smegmatis growth on nitrate as the sole nitrogen source and that the global transcriptional regulator GlnR regulates nasN expression. Moreover, unlike the NADH-dependent heterodimeric NAS enzyme, NasN efficiently supports bacterial growth under nitrate-limiting conditions, likely due to its significantly greater catalytic activity and oxygen tolerance. Results from a phylogenetic analysis suggested that the nasN gene is more recently evolved than those encoding other NASs and that its distribution is limited mainly to Actinobacteria and Proteobacteria. We observed that among mycobacterial species, most fast-growing environmental mycobacteria carry nasN, but that it is largely lacking in slow-growing pathogenic mycobacteria because of multiple independent genomic deletion events along their evolution.
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Affiliation(s)
- Wei Tan
- Department of Microbiology and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong 999077, China.,Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences and Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai 200032, China
| | - Tian-Hua Liao
- Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jin Wang
- College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Yu Ye
- Department of Microbiology and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong 999077, China
| | - Yu-Chen Wei
- Department of Microbiology and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong 999077, China
| | - Hao-Kui Zhou
- Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Youli Xiao
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xiao-Yang Zhi
- Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming 650091, China
| | - Zhi-Hui Shao
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Liang-Dong Lyu
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences and Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai 200032, China
| | - Guo-Ping Zhao
- Department of Microbiology and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong 999077, China .,Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences and Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai 200032, China.,Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.,CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Bio-Med Big Data Center, Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Shanghai-MOST Key Laboratory for Health and Disease Genomics, Chinese National Human Genome Center, Shanghai 201203, China
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24
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Gebbie L, Dam TT, Ainscough R, Palfreyman R, Cao L, Harrison M, O'Hara I, Speight R. A snapshot of microbial diversity and function in an undisturbed sugarcane bagasse pile. BMC Biotechnol 2020; 20:12. [PMID: 32111201 PMCID: PMC7049217 DOI: 10.1186/s12896-020-00609-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/24/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Sugarcane bagasse is a major source of lignocellulosic biomass, yet its economic potential is not fully realised. To add value to bagasse, processing is needed to gain access to the embodied recalcitrant biomaterials. When bagasse is stored in piles in the open for long periods it is colonised by microbes originating from the sugarcane, the soil nearby or spores in the environment. For these microorganisms to proliferate they must digest the bagasse to access carbon for growth. The microbial community in bagasse piles is thus a potential resource for the discovery of useful and novel microbes and industrial enzymes. We used culturing and metabarcoding to understand the diversity of microorganisms found in a uniquely undisturbed bagasse storage pile and screened the cultured organisms for fibre-degrading enzymes. RESULTS Samples collected from 60 to 80 cm deep in the bagasse pile showed hemicellulose and partial lignin degradation. One hundred and four microbes were cultured from different layers and included a high proportion of oleaginous yeast and biomass-degrading fungi. Overall, 70, 67, 70 and 57% of the microbes showed carboxy-methyl cellulase, xylanase, laccase and peroxidase activity, respectively. These percentages were higher in microbes selectively cultured from deep layers, with all four activities found for 44% of these organisms. Culturing and amplicon sequencing showed that there was less diversity and therefore more selection in the deeper layers, which were dominated by thermophiles and acid tolerant organisms, compared with the top of pile. Amplicon sequencing indicated that novel fungi were present in the pile. CONCLUSIONS A combination of culture-dependent and independent methods was successful in exploring the diversity in the bagasse pile. The variety of species that was found and that are known for biomass degradation shows that the bagasse pile was a valuable selective environment for the identification of new microbes and enzymes with biotechnological potential. In particular, lignin-modifying activities have not been reported previously for many of the species that were identified, suggesting future studies are warranted.
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Affiliation(s)
- Leigh Gebbie
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Tuan Tu Dam
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Rebecca Ainscough
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Robin Palfreyman
- Metabolomics Australia, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Li Cao
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Mark Harrison
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Ian O'Hara
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Robert Speight
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia.
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25
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Benoit SL, Maier RJ, Sawers RG, Greening C. Molecular Hydrogen Metabolism: a Widespread Trait of Pathogenic Bacteria and Protists. Microbiol Mol Biol Rev 2020; 84:e00092-19. [PMID: 31996394 PMCID: PMC7167206 DOI: 10.1128/mmbr.00092-19] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Pathogenic microorganisms use various mechanisms to conserve energy in host tissues and environmental reservoirs. One widespread but often overlooked means of energy conservation is through the consumption or production of molecular hydrogen (H2). Here, we comprehensively review the distribution, biochemistry, and physiology of H2 metabolism in pathogens. Over 200 pathogens and pathobionts carry genes for hydrogenases, the enzymes responsible for H2 oxidation and/or production. Furthermore, at least 46 of these species have been experimentally shown to consume or produce H2 Several major human pathogens use the large amounts of H2 produced by colonic microbiota as an energy source for aerobic or anaerobic respiration. This process has been shown to be critical for growth and virulence of the gastrointestinal bacteria Salmonella enterica serovar Typhimurium, Campylobacter jejuni, Campylobacter concisus, and Helicobacter pylori (including carcinogenic strains). H2 oxidation is generally a facultative trait controlled by central regulators in response to energy and oxidant availability. Other bacterial and protist pathogens produce H2 as a diffusible end product of fermentation processes. These include facultative anaerobes such as Escherichia coli, S Typhimurium, and Giardia intestinalis, which persist by fermentation when limited for respiratory electron acceptors, as well as obligate anaerobes, such as Clostridium perfringens, Clostridioides difficile, and Trichomonas vaginalis, that produce large amounts of H2 during growth. Overall, there is a rich literature on hydrogenases in growth, survival, and virulence in some pathogens. However, we lack a detailed understanding of H2 metabolism in most pathogens, especially obligately anaerobic bacteria, as well as a holistic understanding of gastrointestinal H2 transactions overall. Based on these findings, we also evaluate H2 metabolism as a possible target for drug development or other therapies.
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Affiliation(s)
- Stéphane L Benoit
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Robert J Maier
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - R Gary Sawers
- Institute of Microbiology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
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26
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Schmitz RA, Pol A, Mohammadi SS, Hogendoorn C, van Gelder AH, Jetten MSM, Daumann LJ, Op den Camp HJM. The thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV oxidizes subatmospheric H 2 with a high-affinity, membrane-associated [NiFe] hydrogenase. ISME JOURNAL 2020; 14:1223-1232. [PMID: 32042101 PMCID: PMC7174314 DOI: 10.1038/s41396-020-0609-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 12/23/2022]
Abstract
The trace amounts (0.53 ppmv) of atmospheric hydrogen gas (H2) can be utilized by microorganisms to persist during dormancy. This process is catalyzed by certain Actinobacteria, Acidobacteria, and Chloroflexi, and is estimated to convert 75 × 1012 g H2 annually, which is half of the total atmospheric H2. This rapid atmospheric H2 turnover is hypothesized to be catalyzed by high-affinity [NiFe] hydrogenases. However, apparent high-affinity H2 oxidation has only been shown in whole cells, rather than for the purified enzyme. Here, we show that the membrane-associated hydrogenase from the thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV possesses a high apparent affinity (Km(app) = 140 nM) for H2 and that methanotrophs can oxidize subatmospheric H2. Our findings add to the evidence that the group 1h [NiFe] hydrogenase is accountable for atmospheric H2 oxidation and that it therefore could be a strong controlling factor in the global H2 cycle. We show that the isolated enzyme possesses a lower affinity (Km = 300 nM) for H2 than the membrane-associated enzyme. Hence, the membrane association seems essential for a high affinity for H2. The enzyme is extremely thermostable and remains folded up to 95 °C. Strain SolV is the only known organism in which the group 1h [NiFe] hydrogenase is responsible for rapid growth on H2 as sole energy source as well as oxidation of subatmospheric H2. The ability to conserve energy from H2 could increase fitness of verrucomicrobial methanotrophs in geothermal ecosystems with varying CH4 fluxes. We propose that H2 oxidation can enhance growth of methanotrophs in aerated methane-driven ecosystems. Group 1h [NiFe] hydrogenases could therefore contribute to mitigation of global warming, since CH4 is an important and extremely potent greenhouse gas.
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Affiliation(s)
- Rob A Schmitz
- Department of Microbiology, Radboud University, Heyendaalseweg 135, NL-6525 AJ, Nijmegen, The Netherlands
| | - Arjan Pol
- Department of Microbiology, Radboud University, Heyendaalseweg 135, NL-6525 AJ, Nijmegen, The Netherlands
| | - Sepehr S Mohammadi
- Department of Microbiology, Radboud University, Heyendaalseweg 135, NL-6525 AJ, Nijmegen, The Netherlands
| | - Carmen Hogendoorn
- Department of Microbiology, Radboud University, Heyendaalseweg 135, NL-6525 AJ, Nijmegen, The Netherlands
| | - Antonie H van Gelder
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Mike S M Jetten
- Department of Microbiology, Radboud University, Heyendaalseweg 135, NL-6525 AJ, Nijmegen, The Netherlands
| | - Lena J Daumann
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstraβe 5-13, D-81377, München, Germany
| | - Huub J M Op den Camp
- Department of Microbiology, Radboud University, Heyendaalseweg 135, NL-6525 AJ, Nijmegen, The Netherlands.
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27
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Islam ZF, Cordero PRF, Greening C. Putative Iron-Sulfur Proteins Are Required for Hydrogen Consumption and Enhance Survival of Mycobacteria. Front Microbiol 2019; 10:2749. [PMID: 31824474 PMCID: PMC6883350 DOI: 10.3389/fmicb.2019.02749] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 11/12/2019] [Indexed: 01/01/2023] Open
Abstract
Aerobic soil bacteria persist by scavenging molecular hydrogen (H2) from the atmosphere. This key process is the primary sink in the biogeochemical hydrogen cycle and supports the productivity of oligotrophic ecosystems. In Mycobacterium smegmatis, atmospheric H2 oxidation is catalyzed by two phylogenetically distinct [NiFe]-hydrogenases, Huc (group 2a) and Hhy (group 1h). However, it is currently unresolved how these enzymes transfer electrons derived from H2 oxidation into the aerobic respiratory chain. In this work, we used genetic approaches to confirm that two putative iron-sulfur cluster proteins encoded on the hydrogenase structural operons, HucE and HhyE, are required for H2 consumption in M. smegmatis. Sequence analysis show that these proteins, while homologous, fall into distinct phylogenetic clades and have distinct metal-binding motifs. H2 oxidation was reduced when the genes encoding these proteins were deleted individually and was eliminated when they were deleted in combination. In turn, the growth yield and long-term survival of these deletion strains was modestly but significantly reduced compared to the parent strain. In both biochemical and phenotypic assays, the mutant strains lacking the putative iron-sulfur proteins phenocopied those of hydrogenase structural subunit mutants. We hypothesize that these proteins mediate electron transfer between the catalytic subunits of the hydrogenases and the menaquinone pool of the M. smegmatis respiratory chain; however, other roles (e.g., in maturation) are also plausible and further work is required to resolve their role. The conserved nature of these proteins within most Hhy- or Huc-encoding organisms suggests that these proteins are important determinants of atmospheric H2 oxidation.
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Affiliation(s)
| | | | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
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28
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Slobodkin A, Slobodkina G, Allioux M, Alain K, Jebbar M, Shadrin V, Kublanov I, Toshchakov S, Bonch-Osmolovskaya E. Genomic Insights into the Carbon and Energy Metabolism of a Thermophilic Deep-Sea Bacterium Deferribacter autotrophicus Revealed New Metabolic Traits in the Phylum Deferribacteres. Genes (Basel) 2019; 10:genes10110849. [PMID: 31717820 PMCID: PMC6896113 DOI: 10.3390/genes10110849] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 01/12/2023] Open
Abstract
Information on the biochemical pathways of carbon and energy metabolism in representatives of the deep lineage bacterial phylum Deferribacteres are scarce. Here, we report the results of the sequencing and analysis of the high-quality draft genome of the thermophilic chemolithoautotrophic anaerobe Deferribacter autotrophicus. Genomic data suggest that CO2 assimilation is carried out by recently proposed reversible tricarboxylic acid cycle (“roTCA cycle”). The predicted genomic ability of D. autotrophicus to grow due to the oxidation of carbon monoxide was experimentally proven. CO oxidation was coupled with the reduction of nitrate to ammonium. Utilization of CO most likely involves anaerobic [Ni, Fe]-containing CO dehydrogenase. This is the first evidence of CO oxidation in the phylum Deferribacteres. The genome of D. autotrophicus encodes a Nap-type complex of nitrate reduction. However, the conversion of produced nitrite to ammonium proceeds via a non-canonical pathway with the participation of hydroxylamine oxidoreductase (Hao) and hydroxylamine reductase. The genome contains 17 genes of putative multiheme c-type cytochromes and “e-pilin” genes, some of which are probably involved in Fe(III) reduction. Genomic analysis indicates that the roTCA cycle of CO2 fixation and putative Hao-enabled ammonification may occur in several members of the phylum Deferribacteres.
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Affiliation(s)
- Alexander Slobodkin
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (G.S.); (V.S.); (I.K.); (S.T.); (E.B.-O.)
- Correspondence:
| | - Galina Slobodkina
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (G.S.); (V.S.); (I.K.); (S.T.); (E.B.-O.)
| | - Maxime Allioux
- Univ Brest, CNRS, Ifremer, LIA1211, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, F-29280 Plouzané, France; (M.A.); (K.A.); (M.J.)
| | - Karine Alain
- Univ Brest, CNRS, Ifremer, LIA1211, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, F-29280 Plouzané, France; (M.A.); (K.A.); (M.J.)
| | - Mohamed Jebbar
- Univ Brest, CNRS, Ifremer, LIA1211, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, F-29280 Plouzané, France; (M.A.); (K.A.); (M.J.)
| | - Valerian Shadrin
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (G.S.); (V.S.); (I.K.); (S.T.); (E.B.-O.)
| | - Ilya Kublanov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (G.S.); (V.S.); (I.K.); (S.T.); (E.B.-O.)
| | - Stepan Toshchakov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (G.S.); (V.S.); (I.K.); (S.T.); (E.B.-O.)
| | - Elizaveta Bonch-Osmolovskaya
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (G.S.); (V.S.); (I.K.); (S.T.); (E.B.-O.)
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29
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Cordero PRF, Grinter R, Hards K, Cryle MJ, Warr CG, Cook GM, Greening C. Two uptake hydrogenases differentially interact with the aerobic respiratory chain during mycobacterial growth and persistence. J Biol Chem 2019; 294:18980-18991. [PMID: 31624148 DOI: 10.1074/jbc.ra119.011076] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/12/2019] [Indexed: 12/11/2022] Open
Abstract
To persist when nutrient sources are limited, aerobic soil bacteria metabolize atmospheric hydrogen (H2). This process is the primary sink in the global H2 cycle and supports the productivity of microbes in oligotrophic environments. H2-metabolizing bacteria possess [NiFe] hydrogenases that oxidize H2 to subatmospheric concentrations. The soil saprophyte Mycobacterium smegmatis has two such [NiFe] hydrogenases, designated Huc and Hhy, that belong to different phylogenetic subgroups. Both Huc and Hhy are oxygen-tolerant, oxidize H2 to subatmospheric concentrations, and enhance bacterial survival during hypoxia and carbon limitation. Why does M. smegmatis require two hydrogenases with a seemingly similar function? In this work, we resolved this question by showing that Huc and Hhy are differentially expressed, localized, and integrated into the respiratory chain. Huc is active in late exponential and early stationary phases, supporting energy conservation during mixotrophic growth and transition into dormancy. In contrast, Hhy is most active during long-term persistence, providing energy for maintenance processes following carbon exhaustion. We also show that Huc and Hhy are obligately linked to the aerobic respiratory chain via the menaquinone pool and are differentially affected by respiratory uncouplers. Consistently, these two enzymes interacted differentially with the respiratory terminal oxidases. Huc exclusively donated electrons to, and possibly physically associated with, the proton-pumping cytochrome bcc-aa 3 supercomplex. In contrast the more promiscuous Hhy also provided electrons to the cytochrome bd oxidase complex. These results indicate that, despite their similar characteristics, Huc and Hhy perform distinct functions during mycobacterial growth and survival.
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Affiliation(s)
- Paul R F Cordero
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Rhys Grinter
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Kiel Hards
- Department of Microbiology and Immunology, University of Otago, Dunedin, OTA 9016, New Zealand
| | - Max J Cryle
- Monash Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Coral G Warr
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia.,School of Medicine, University of Tasmania, Hobart, TAS 7000, Australia
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin, OTA 9016, New Zealand
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
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Two Chloroflexi classes independently evolved the ability to persist on atmospheric hydrogen and carbon monoxide. ISME JOURNAL 2019; 13:1801-1813. [PMID: 30872805 PMCID: PMC6776052 DOI: 10.1038/s41396-019-0393-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/21/2019] [Accepted: 02/20/2019] [Indexed: 11/29/2022]
Abstract
Most aerobic bacteria exist in dormant states within natural environments. In these states, they endure adverse environmental conditions such as nutrient starvation by decreasing metabolic expenditure and using alternative energy sources. In this study, we investigated the energy sources that support persistence of two aerobic thermophilic strains of the environmentally widespread but understudied phylum Chloroflexi. A transcriptome study revealed that Thermomicrobium roseum (class Chloroflexia) extensively remodels its respiratory chain upon entry into stationary phase due to nutrient limitation. Whereas primary dehydrogenases associated with heterotrophic respiration were downregulated, putative operons encoding enzymes involved in molecular hydrogen (H2), carbon monoxide (CO), and sulfur compound oxidation were significantly upregulated. Gas chromatography and microsensor experiments showed that T. roseum aerobically respires H2 and CO at a range of environmentally relevant concentrations to sub-atmospheric levels. Phylogenetic analysis suggests that the hydrogenases and carbon monoxide dehydrogenases mediating these processes are widely distributed in Chloroflexi genomes and have probably been horizontally acquired on more than one occasion. Consistently, we confirmed that the sporulating isolate Thermogemmatispora sp. T81 (class Ktedonobacteria) also oxidises atmospheric H2 and CO during persistence, though further studies are required to determine if these findings extend to mesophilic strains. This study provides axenic culture evidence that atmospheric CO supports bacterial persistence and reports the third phylum, following Actinobacteria and Acidobacteria, to be experimentally shown to mediate the biogeochemically and ecologically important process of atmospheric H2 oxidation. This adds to the growing body of evidence that atmospheric trace gases are dependable energy sources for bacterial persistence.
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Kessler AJ, Chen YJ, Waite DW, Hutchinson T, Koh S, Popa ME, Beardall J, Hugenholtz P, Cook PLM, Greening C. Bacterial fermentation and respiration processes are uncoupled in anoxic permeable sediments. Nat Microbiol 2019; 4:1014-1023. [DOI: 10.1038/s41564-019-0391-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 01/28/2019] [Indexed: 11/09/2022]
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Hausmann B, Pelikan C, Herbold CW, Köstlbacher S, Albertsen M, Eichorst SA, Glavina Del Rio T, Huemer M, Nielsen PH, Rattei T, Stingl U, Tringe SG, Trojan D, Wentrup C, Woebken D, Pester M, Loy A. Peatland Acidobacteria with a dissimilatory sulfur metabolism. THE ISME JOURNAL 2018; 12:1729-1742. [PMID: 29476143 PMCID: PMC6018796 DOI: 10.1038/s41396-018-0077-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/21/2017] [Accepted: 01/20/2018] [Indexed: 12/25/2022]
Abstract
Sulfur-cycling microorganisms impact organic matter decomposition in wetlands and consequently greenhouse gas emissions from these globally relevant environments. However, their identities and physiological properties are largely unknown. By applying a functional metagenomics approach to an acidic peatland, we recovered draft genomes of seven novel Acidobacteria species with the potential for dissimilatory sulfite (dsrAB, dsrC, dsrD, dsrN, dsrT, dsrMKJOP) or sulfate respiration (sat, aprBA, qmoABC plus dsr genes). Surprisingly, the genomes also encoded DsrL, which so far was only found in sulfur-oxidizing microorganisms. Metatranscriptome analysis demonstrated expression of acidobacterial sulfur-metabolism genes in native peat soil and their upregulation in diverse anoxic microcosms. This indicated an active sulfate respiration pathway, which, however, might also operate in reverse for dissimilatory sulfur oxidation or disproportionation as proposed for the sulfur-oxidizing Desulfurivibrio alkaliphilus. Acidobacteria that only harbored genes for sulfite reduction additionally encoded enzymes that liberate sulfite from organosulfonates, which suggested organic sulfur compounds as complementary energy sources. Further metabolic potentials included polysaccharide hydrolysis and sugar utilization, aerobic respiration, several fermentative capabilities, and hydrogen oxidation. Our findings extend both, the known physiological and genetic properties of Acidobacteria and the known taxonomic diversity of microorganisms with a DsrAB-based sulfur metabolism, and highlight new fundamental niches for facultative anaerobic Acidobacteria in wetlands based on exploitation of inorganic and organic sulfur molecules for energy conservation.
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Affiliation(s)
- Bela Hausmann
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Claus Pelikan
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Craig W Herbold
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Stephan Köstlbacher
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Mads Albertsen
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark
| | - Stephanie A Eichorst
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | | | - Martin Huemer
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Per H Nielsen
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark
| | - Thomas Rattei
- Division of Computational Systems Biology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Ulrich Stingl
- Department for Microbiology and Cell Science, Fort Lauderdale Research and Education Center, UF/IFAS, University of Florida, Davie, FL, USA
| | - Susannah G Tringe
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Daniela Trojan
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Cecilia Wentrup
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Dagmar Woebken
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Michael Pester
- Department of Biology, University of Konstanz, Konstanz, Germany.
- Leibniz Institute DSMZ, Braunschweig, Germany.
| | - Alexander Loy
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
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Eichorst SA, Trojan D, Roux S, Herbold C, Rattei T, Woebken D. Genomic insights into the Acidobacteria reveal strategies for their success in terrestrial environments. Environ Microbiol 2018; 20:1041-1063. [PMID: 29327410 PMCID: PMC5900883 DOI: 10.1111/1462-2920.14043] [Citation(s) in RCA: 144] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 12/16/2017] [Accepted: 01/08/2018] [Indexed: 12/11/2022]
Abstract
Members of the phylum Acidobacteria are abundant and ubiquitous across soils. We performed a large-scale comparative genome analysis spanning subdivisions 1, 3, 4, 6, 8 and 23 (n = 24) with the goal to identify features to help explain their prevalence in soils and understand their ecophysiology. Our analysis revealed that bacteriophage integration events along with transposable and mobile elements influenced the structure and plasticity of these genomes. Low- and high-affinity respiratory oxygen reductases were detected in multiple genomes, suggesting the capacity for growing across different oxygen gradients. Among many genomes, the capacity to use a diverse collection of carbohydrates, as well as inorganic and organic nitrogen sources (such as via extracellular peptidases), was detected - both advantageous traits in environments with fluctuating nutrient environments. We also identified multiple soil acidobacteria with the potential to scavenge atmospheric concentrations of H2 , now encompassing mesophilic soil strains within the subdivision 1 and 3, in addition to a previously identified thermophilic strain in subdivision 4. This large-scale acidobacteria genome analysis reveal traits that provide genomic, physiological and metabolic versatility, presumably allowing flexibility and versatility in the challenging and fluctuating soil environment.
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Affiliation(s)
- Stephanie A. Eichorst
- Division of Microbial Ecology, Department of Microbiology and Ecosystem ScienceResearch Network “Chemistry Meets Biology”, University of ViennaViennaAustria
| | - Daniela Trojan
- Division of Microbial Ecology, Department of Microbiology and Ecosystem ScienceResearch Network “Chemistry Meets Biology”, University of ViennaViennaAustria
| | - Simon Roux
- Department of EnergyJoint Genome InstituteWalnut CreekCAUSA
| | - Craig Herbold
- Division of Microbial Ecology, Department of Microbiology and Ecosystem ScienceResearch Network “Chemistry Meets Biology”, University of ViennaViennaAustria
| | - Thomas Rattei
- Division of Computational Systems Biology, Department of Microbiology and Ecosystem ScienceResearch Network “Chemistry Meets Biology”, University of ViennaViennaAustria
| | - Dagmar Woebken
- Division of Microbial Ecology, Department of Microbiology and Ecosystem ScienceResearch Network “Chemistry Meets Biology”, University of ViennaViennaAustria
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34
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Bay S, Ferrari B, Greening C. Life without water: how do bacteria generate biomass in desert ecosystems? MICROBIOLOGY AUSTRALIA 2018. [DOI: 10.1071/ma18008] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Many of the world's most arid deserts harbour surprisingly diverse communities of heterotrophic bacteria. These organisms persist in surface soils under extreme climatic conditions, despite lacking obvious energy inputs from phototrophic primary producers. A longstanding conundrum has been how these communities sustain enough energy to maintain their diversity and biomass. We recently helped to resolve this conundrum by demonstrating that some desert communities are structured by a minimalistic mode of chemosynthetic primary production, where atmospheric trace gases, not sunlight, serve as the main energy sources. These findings are supported by pure culture studies that suggest atmospheric trace gases are dependable energy sources for the long-term survival of dormant soil bacteria. We predict that atmospheric trace gases may be a major energy source for desert ecosystems worldwide.
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